L. David Baron wrote:
> In CSS 2.1 we added the text:
> # The computed value of "font-weight" is either:
> #
> # * one of the legal number values, or
> # * one of the legal number values combined with one or more of
> # the relative values (bolder or lighter). This type of
> # computed values is necessary to use when the font in
> # question does not have all weight variations that are
> # needed.
> #
> # CSS 2.1 does not specify how the computed value of font-weight
> # is represented internally or externally.
> http://www.w3.org/TR/2007/CR-CSS21-20070719/fonts.html#font-boldness
>
> This text explains how the computed value of 'font-weight' works to
> yield the next-bolder or next-lighter face within the font family,
> even when the font family actually used to render a character can
> depend on what the character is (and whether the font has it).
>
>
> This disagrees with some existing text that is held over from CSS1.
> We should remove the following parts of the bullets in the previous
> unordered list:
>
> (from the 'bolder' bullet)
> # If there is no such weight, it simply results in the next darker
> # numerical value (and the font remains unchanged), unless the
> # inherited value was '900' in which case the resulting weight is
> # also '900'.
>
> (from the 'lighter' bullet)
> # , unless there is no such font, in which case it selects the
> # next lighter numerical value (and keeps the font unchanged)
>
> These are incorrect (and don't make any sense anyway, since it's not
> possible to do the computation that it describes, since there are
> multiple font families involved).
Recorded as CSS2.1 Issue 48:
http://csswg.inkedblade.net/spec/css2.1#issue-48
~fantasai